The present invention relates to thermal regulation devices used for regulating, to a desired positive or negative value, the temperature of an element, particularly a semi-conductor component, during electric testing under variable thermal conditions (e.g. between -65.degree. and +210.degree. C.), this temperature regulation being obtained by blowing a gas at the desired temperature on said element, this thermal regulation device comprising a body supporting an intake duct for the gas at the appropriate temperature and means for insulating the element with respect to the ambient atmosphere, these insulating means comprising an insulating bell adapted to cover the element and supported slidingly by the free end of said duct, resilient means being inserted between the insulating bell and the body of the device for holding said bell in sealed resilient application against the support of the element with which is cooperates.
FIG. 1 of the accompanying drawings shows schematically, in cross section, an arrangement of a device in accordance with the state of the art. The body 1 of the device (which is simply suggested in the drawing and whose inner equipment has not been shown)--which may be suspended for example from a bracket facilitating its positioning and removal--contains a duct 2 conveying the thermal regulation gas (at a positive or negative temperature) supplied by a source (not shown). The lower end 3 of duct 2 is surrounded by a sliding sleeve 4 urged resiliently downwards by a helical spring 5 surrounding the lower end of duct 2. Sleeve 4 supports a bell 6, e.g. made from rubber, which is dimensioned and configured so as to be able to cover an element 7, e.g. an integrated circuit during electric testing under variable thermal conditions. The lower edge of bell 6 is held sealingly and resiliently applied, by spring 5, against the surface of support 8 of the component 7 (in the drawing support 8 is shown with element 7, alone, the electric connector providing the mechanical retention of the component and the electric connections with the test circuit not being shown for simplifying the representation).
Furthermore, an enclosure 11 for recovering the gases, fast with the lower portion of body 1, surrounds bell 6 and is defined by an insulating ceiling 9a through which duct 2 passes and by sidewalls 9 formed by a double glass partition.
The temperature regulation gas is fed into bell 6 through duct 2 whose lower end 3 opens above element 7, escapes through orifices 10 pierced in the sidewalls thereof, then is finally discharged from enclosure 11 through a discharge orifice 12 provided in ceiling 9a. A dry air intake is provided through an orifice 13, emerging between the two glass walls of the double wall 9 so as to avoid condensation of the humidity of the ambient atmosphere and frosting up thereof during low temperature tests.
This known arrangement has numerous drawbacks.
First of all, this structure is as a whole heavy, cumbersome and complex and therefore expensive to purchase and not very practical in use. In addition, the presence of the double glass wall 9 limits the vertical free movement of bell 6. Moreover, in order to avoid discharge of the gases into the atmosphere directly on leaving give rise to frosting up, during low temperature tests, in the immediate vicinity of the device and so as to avoid also the discharge of gas at the height of the face of the operator controlling the operation of the apparatus, a discharge tube 14 is fixed to orifice 12 which is sufficiently long and conformed so that the gases are discharged further away; however, this tube 19 is cumbersome and hinders the handling of the device.
Different tests have been made to attempt to simplify this known structure, but none has given satisfaction up to now.